Consumers worldwide experience color damage to their clothing, upholstery, the interior of their automobiles, etc., from exposure to the sun. For example, color damage to clothing during drying and during wear is especially severe for those consumers living in tropical and subtropical climates. Despite extensive efforts by the industry to develop light stable surfaces such as upholstery, and automobile interiors, to develop light stable dyes, after-treatments to improve light-fastness of dyes for textiles, and plastics which resist fading, the fading of surfaces from sunlight still remains a problem.
Antioxidant compounds are known in the art for various benefits. For example, EPA 273,011, Ravichandran et al., published Jun. 29, 1988, Ciba-Geigy, teaches N,N-bis(hydroxyethyl)hydroxylamine esters to stabilize organic materials (i.e. organic polyolefins, elastomers and lubricating oils) against oxidative, thermal and actinic degradation.
U.S. Pat. No. 5,081,280, Takee et al., issued on Jan. 14, 1992, Yoshitomi Pharmaceutical Industries, Ltd., teaches a process for producing esterified, sterically hindered phenolic compounds as an antioxidant for organic materials with decreased reaction times and less discoloration of the compound. These compounds do not contain an amine function as do the compounds of the present invention.
U.S. Pat. No. 3,330,859, Dexter et al., issued Jul. 11, 1967, Geigy Chemical Corporation, teaches sterically hindered phenolic carboxylic acid esters which are useful to stabilize organic materials such as organic polymers and copolymers, lubricating oils of the aliphatic ester type, hydrocarbon material such as gasoline, etc. These compounds do not contain an amine function as do the compounds of the present invention.
U.S. Pat. No. 3,920,729, Sagawa, et al., issued Nov. 18, 1975, Sumitomo Chemical Co., Ltd., teaches sterically hindered phenolic esterified isopropanolamines for the stabilization of organic substances, particularly polyolefins, halogenated vinyl polymers, copolymers of halogenated vinyl and unsaturated polymerizable compound, copolymers of acrylonitrile, butadiene and styrene, polyurethane, polyamides, polyesters, polyacetals, polycarbonates, polystyrene and natural and synthetic rubber. These compounds have methyl groups attached to the beta carbon atom with regard to the nitrogen atom, for enhanced thermal stability with reduced blooming when mixed with a polyolefin.
U.S. Pat. No. 4,305,868, Wheeler et al., issued December 15, 1981, Uniroyla, Inc., teaches sterically hindered phenolic substituted esterbisamides as antioxidants useful for the protection of organic materials such as synthetic and natural rubbers, plastics and petroleum products against oxidative degradation.
Furthermore, U.S. Pat. No. 4,900,469, Clorox, teaches antioxidants in detergents for bleach stability. Antioxidants have been used in softeners and detergents to prevent fabric yellowing and to control malodor. (See, JP 72/116,783, Kao.)
Because antioxidant compounds are expensive, it is desirable to select and utilize the most efficient compounds in order to minimize the cost of formulating with these compounds.
However, it is now recognized that antioxidants adaptable for various other applications are not always satisfactory for other applications such as for use in foods (as a preservative), cosmetics (as a preservative), in rinse added fabric softener compositions, dryer added fabric softener compositions, detergents, fabric pretreatment or spray on products, hard surface cleaners, compositions for use on floor coverings (i.e. carpet, vinyl), automotive upholstery, upholstery, hair care products, vinyl treatments and plastics.
With regard to textiles, it has now been discovered that visible light is responsible for a significant amount of dye fading on clothing. For example, visible light has a higher contribution to fading than UV-A, which has a higher contribution to fading than UV-B. Antioxidants can provide broader sun-fade fabric protection for surfaces than sunscreen agents because antioxidant effectiveness is not dependent upon the absorption of light.
Therefore, an object of the present invention is to provide antioxidant compounds, effective at low levels, which will reduce the rate of degradation and/or discoloration (i.e. sun-fading) of a variety of surfaces.
All of the above patents and patent applications are incorporated herein by reference.